Validity of the Myers Briggs Type Indicator®: is the MBTI® Scientific?

Although the Myers Briggs Type Indicator® is the most widely used personality assessment in the world, it's also a tool that people love to hate. It has been alternately called "totally meaningless," "unscientific," and "the fad that won't die." Critics of the MBTI® assessment's validity claim that the system is nothing more than pseudoscience. Is it possible that the over two million people who take the MBTI each year have fallen victim to a massive scam?

Those who denounce Myers and Briggs' theory as having no validity typically point to three major challenges. Some of these challenges relate to the test itself, while others point to issues with the theory behind the test.

Reliability and Validity Problems with the MBTI Assessment

Myers and Briggs felt that personality could be defined in terms of dichotomies, an either-or choice that separates people clearly into one of two camps. For example, in Myers and Briggs' thinking, a person is either an Extravert or an Introvert. Unfortunately, all scientific evidence points to this assumption being false. When measuring levels of Extraversion/Introversion in a population, the distribution of this trait follows a normal curve, with most people being neither particularly Extraverted or Introverted, and a few people showing a clear preference for one style over the other.

Thus, it is somewhat arbitrary to attempt to draw a distinction between Extraverts and Introverts. If we imagine a hypothetical personality test scoring Extraversion on a 100-point scale, we might classify someone with a score of 49 as an Introvert, and another individual scoring 51 as an Extravert. However, there is little valid rationale for doing so, as our two hypothetical people only differed in their absolute scores by two points—and their real-life expressions of this trait are probably indistinguishable. This is a genuine and fundamental problem with the validity of Myers and Briggs' theory.

This issue is closely related to the second major complaint about the MBTI assessment, which is that it has poor test-retest reliability. This means that a person who takes the MBTI assessment on two separate occasions is fairly likely to get different results from one instance to another. Most of this variability is due to the dichotomous nature of the scoring; people who are close to the average score for a particular scale can easily fall on the opposite side of the dichotomy when tested again.

Additionally, many critics of the MBTI's validity cite its poor predictive value. Typically, a psychometric assessment is considered valid when it can predict real-world outcomes like marital satisfaction or depression risk. In the case of the MBTI, criticism often centers around its inability to predict job performance.

However, predictive validity is only a concern for the factors that the assessment is intended to measure. We do not declare that our bathroom scale is useless because it cannot measure our height. In fact, the MBTI assessment was never intended to predict job performance; its creators specifically noted that any type can be successful in any job. It is more accurate to say that we expect MBTI scores to correlate with job choice or job satisfaction—and validation studies have shown that both effects can be observed. In short, the MBTI does have predictive value, when you look at the factors it is intended to predict.

Why Does Myers & Briggs' Model Persist?

While the concerns about the MBTI's predictive validity are based on false assumptions, the other issues with Myers and Briggs' theory are not so easily dismissed. It is, in fact, somewhat unscientific to attempt to sort people into types, and trying to do so causes structural issues in designing a related assessment. Some have argued that these problems should prompt us to toss Myers and Briggs' system altogether, in favor of more scientifically sound models like the Big Five. But the public has not caught on, and the MBTI continues to enjoy wide popularity.

Although Myers and Briggs' model of personality has some fundamental flaws, it offers a major advantage over systems like the Big Five—it works the way our brains work. The human mind is built to categorize, and we like categorizing people just as much as anything else. Ever since Hippocrates decided that people could be classified as "phlegmatic" or "choleric," we've been looking for ways to make sense of human behavior by sorting people into groups.

Although scientific researchers prefer to describe personality with the more accurate Big Five, the average person doesn't tend to be captivated by a system that describes people as "high in Openness, average in Extraversion, low in Agreeableness," and so on. It doesn't exactly roll off the tongue in the same way as does "I'm an INFJ!" For this reason, people looking to explore personality in a non-research setting—in business, career coaching, or couples counseling—tend to gravitate towards a model that is easier to wrap their heads around. In many cases, this model is Myers and Briggs' theory.

Myers Briggs vs. Big Five

Although many critics compare Myers and Briggs' validity unfavorably to the Big Five, this argument overlooks a central fact: Myers and Briggs' four personality preferences describe essentially the same constructs as four of the Big Five personality traits. It is specious, therefore, to insist that the MBTI has no validity in comparison with the Big Five—they are, in many ways, describing the same phenomena.

Big Five researchers Costa and McCrae compared scores on the MBTI assessment with the Big-Five-based NEO Pesonality Inventory and found significant correlations between scores on related constructs. Specifically, they found that the dichotomies outlined by Myers and Briggs corresponded to four of the Big Five factors, in the following way:

Myers and Briggs' Theory

Big Five Model

EXTRAVERSION VS. INTROVERSION

Your preference for where you get your energy: from other people, or from time alone.

EXTRAVERSION

Describes how much pleasure and reward a person gains from interacting with the world. High scorers are sociable, active, ambitious, and more likely to experience positive emotions.

SENSING VS INTUITION

Your preference for how you take in information: through your five senses, or through a "sixth sense" of intuition.

OPENNESS

Describes a person's tendency to think in abstract, imaginative ways. High scorers are more likely to appreciate art and cultural activities and to adopt unconventional ideas.

THINKING VS. FEELING

Your preference for how you make decisions: using logic and objectivity, or moral values and personal concerns.

AGREEABLENESS

Describes how inclined a person is to empathize and cooperate with others. High scorers are compassionate, accommodating, and altruistic.

JUDGING VS. PERCEIVING

Your preference for how you organize your life: keeping things planned and organized, or open and spontaneous.

CONSCIENTIOUSNESS

Describes how goal-oriented and persistent a person is. High scorers are hardworking, resistant to distractions, and responsible.

The fifth Big Five trait, Neuroticism, has no correlate in Myers and Briggs' framework, although one could argue that because it is a topic with potentially sensitive implications (being related to mental illness, for one) that excluding it is actually a benefit in certain situations, for instance in the workplace.

Overcoming the Challenges of Myers and Briggs' Theory

Whatever the issues with the MBTI assessment and its theory of sixteen personality types, it is clear that a tremendous number of individuals and organizations are not going to give up their attachment to this system of understanding people. Myers and Briggs' model does offer benefits that other, more scientifically robust theories do not, in that it is easily understood and used by laypeople. However, we can assume that the system will only become more useful if some of the key problems are addressed.

The first suggestion for improvement is proposed by psychologist John A. Johnson. Observing the overlap between Myers and Briggs' four preferences and the Big Five personality factors, Johnson asserts that there is genuine value in the MBTI and similar assessments based on the sixteen-type theory. He proposes that type assessments could be made acceptably valid by changing the approach to reporting results—specifically, that reporting results on a scale, rather than as an either-or dichotomy, would allow for more nuance and ambiguity in our description of people. Some modern assessments based on Myers and Briggs' theory, such as the TypeFinder personality assessment, adopt Johnson's suggested approach.

Additionally, proponents of the MBTI and typology theory stress the importance of keeping personality type results in perspective. The Myers-Briggs Company provides pointed warnings against using the MBTI assessment in hiring, stating plainly that it has no predictive value and is thus unethical to use in such a setting. Even in situations where personality type assessments are generally considered appropriate, such as career counseling, test results should not be looked upon as a sort of crystal ball. Although many have benefited from exploring how their personality type might point them to a particular career, taking a personality test is no substitute for thorough self-reflection and research. Similarly, when used in a business setting, personality types are best used to better understand coworkers and their work styles, not to pigeonhole people or limit their potential.

The MBTI assessment and the sixteen-type theory have been subject to quite a bit of criticism, some of it valid. However, its widespread use would seem to indicate that many people find it worthwhile, even indispensable. Although there are genuine, evidence-based challenges to Myers and Briggs' system, changing the way we think about the model can help us to use this framework in a productive way.

Myers-Briggs Type Indicator, Myers-Briggs, and MBTI are registered trademarks of The Myers & Briggs Foundation in the United States and other countries. Truity has no affiliation with the organizations publishing or holding rights to the MBTI® assessment.

Sources

MBTI Manual